Poly(butylene succinate) ionomers and their use as compatibilizers in nanocomposites

Abstract

A series of low-molecular-weight poly(butylene succinate-co-glutarate-co-2-trimethylammonium chloride glutarate) terpolyester ionomers containing 35% mol of total glutarate units but varying in the content of charged units were synthesized by polycondensation at mild temperatures using a scandium catalyst. The terpolyester ionomers started to decompose at the temperatures of >175°C and all of them were semicrystalline and have glass transition temperature similar to poly(butylene succinate) (PBS). These terpolyesters were used to compatibilize the nanocomposites made of PBS-cloisite (CL) prepared by melt extrusion. X-ray diffraction revealed that an intercalated structure was present in these nanocomposites. The thermal properties of the three-component mixtures did not differ substantially from those of PBS–CL but the mechanical properties were significantly improved by the addition of the ionomer, in particular tenacity. The beneficial effect afforded by the terpolyester ionomer was attributed to its ability for strengthening the binding between the PBS and the nanoclay.A series of low-molecular-weight poly(butylene succinate-co-glutarate-co-2-trimethylammonium chloride glutarate) terpolyester ionomers containing 35% mol of total glutarate units but varying in the content of charged units were synthesized by polycondensation at mild temperatures using a scandium catalyst. The terpolyester ionomers started to decompose at the temperatures of >175°C and all of them were semicrystalline and have glass transition temperature similar to poly(butylene succinate) (PBS). These terpolyesters were used to compatibilize the nanocomposites made of PBS-cloisite (CL) prepared by melt extrusion. X-ray diffraction revealed that an intercalated structure was present in these nanocomposites. The thermal properties of the three-component mixtures did not differ substantially from those of PBS–CL but the mechanical properties were significantly improved by the addition of the ionomer, in particular tenacity. The beneficial effect afforded by the terpolyester ionomer was attributed to its ability for strengthening the binding between the PBS and the nanoclay.